Reactivity investigation on chemical looping gasification of biomass char using nickel ferrite oxygen carrier

Chemical looping gasification (CLG) involves the use of an oxygen carrier (OC) which transfers oxygen from air to solid fuel to convert the fuel into synthesis gas, and the traditional gasifying agents such as oxygen-enriched air or high temperature steam are avoided. In order to improve the reactivity of OC with biomass char, facilitating biomass high-efficiency conversion, a compound Fe/Ni bimetallic oxide (NiFe₂O₄) was used as an OC in the present work. Effect of OC content and oxygen sources on char gasification were firstly investigated through a TG reactor. When the OC content in mixture sample attains 65 wt.%, the sample shows the maximum weight loss rate at relatively low temperature, indicating that it is very favorable for the redox reactions between OC and biomass char. The NiFe₂O₄ OC exhibits a good performance for char gasification, which is obvious higher than that of individual Fe₂O₃ OC and mechanically mixed Fe₂O₃ + NiO OC due to the Fe/Ni synergistic effect in unique spinel structure. According to the TGA experimental results, effect of the steam content and cyclic numbers on char gasification were investigated in a fixed bed reactor. Either too low steam content or too high steam content doesn't facilitate the char gasification. And suitable steam content of 56.33% is determined with maximum carbon conversion of 88.12% and synthesis gas yield of 2.58 L/g char. The reactivity of NiFe₂O₄ OC particles shows a downtrend within 20 cycles (～64 h) due to the formation of Fe₂O₃ phase, which is derived from the iron element divorced from the Fe/Ni spinel structure. Secondly, the sintering of OC particles and ash deposit on the surface are also the reasons for the deactivation of NiFe₂O₄ OC. However, the carbon conversion and synthesis gas yield at the 20th cycle are still higher than those of the blank experiment. It indicates that the reactivity of NiFe₂O₄ OC can be maintained at a relatively long time and NiFe₂O₄ material can be used as a good OC candidate for char gasification in the long time running.     

Chemical looping steam reforming of bio-oil for hydrogen-rich syngas production: Effect of doping on LaNi0.8Fe0.2O3 perovskite

Chemical looping steam reforming of bio-oil is novel conversion technology utilizing waste energy, which is an advantage to reduce cost and improve environmental. However, complex reaction process between oxygen carrier and bio-oil constrain its development. In this study, perovskite based La_0.8M_0.2Ni_0.8Fe_0.2O₃ (M = Ca, Ce and Zr) were investigated as an oxygen carrier for chemical looping steam reforming of bio-oil model reaction. The perovskites were prepared via sol-gel method and the effect of doping for reforming of acetic acid as bio-oil model compound is also investigated. Among all the perovskite tested, Ce doped La_0.8Ce_0.2Ni_0.8Fe_0.2O₃ oxygen carrier gave superior and stable catalytic performance for 1440 min at 600 °C and steam/carbon mole ratio (S/C = 2). The fresh and spent oxygen carriers were characterized using XRD, H₂-TPR, CO₂-TPD, TG-DTG, Dielectric constant, Raman, XPS and XANES. Doping with base metal generally, improved coke resistance ability of the perovskite. CO₂-TPD and XPS analysis reveal that the highest carbon resistance for La_0.8Ce_0.2Ni_0.8Fe_0.2O₃ perovskite is due to enhanced stronger surface basicity and oxygen adsorption. From DFT simulation and Dielectric constant results, the better activity for La_0.8Ce_0.2Ni_0.8Fe_0.2O₃ is attributed to its adsorption ability of reactants, oxygen and electron transfer from sub-surface to surface of the perovskite.     

Chemical looping gasification of rice husk to produce hydrogen-rich syngas under different oxygen carrier preparation methods

The chemical looping gasification (CLG) of rice husk was conducted in a small fixed-bed reactor to investigate the effects of oxygen carrier preparation methods, active components, Fe loadings, water inflow and successive redox cycles. The gas content, the relative gas concentration, lower heating value of syngas (LHV), carbon conversion efficiency, gasification efficiency, H₂-TPR, XRD, BET and SEM were analyzed to obtain CLG reaction characterization and comprehensive performance of oxygen carrier. The results showed that compared with several methods and active components, the coprecipitation method with a Fe:Al ratio of 2 was the best preparation method for oxygen carrier. Furthermore, the H₂ concentration was 57.29%, while the gasification efficiency and carbon conversion efficiency were 95.79% and 51.56%. Meanwhile, the oxygen carrier prepared by coprecipitation had a greater performance of oxygen release and reduction. There was an optimal water inflow to obtain the highest gas content, carbon conversion efficiency and gasification efficiency. Thereinto, the H₂ concentration was stable at 54.07–57.65%. And the highest gas content of 78.33% and carbon conversion efficiency of 54.42% were obtained at a water inflow of 14.0 mL/h, while the highest gasification efficiency of 95.79% was obtained at 16.8 mL/h. In addition, after ten successive redox cycles, the gasification performance, crystal size, specific surface area and pore structure were relatively stable. Moreover, the material composition remained basically unchanged.     

Using chemical looping gasification with Fe2O3/Al2O3 oxygen carrier to produce syngas (H2+CO) from rice straw

The chemical looping gasification of rice straw using Fe₂O₃/Al₂O₃ as oxygen carrier was studied at reaction time of 5–25 min, steam-to-biomass (S/B) ratio of 2.0–4.8, reaction temperature of 750–950 °C, and oxygen carrier-to-biomass of 1.0. The gasification can be regarded completed in 20-min reaction. There exist an optimal S/B ratio of 2.8 and reaction temperature of 900 °C leading to maximum performances yielded are 1.22 Nm³/kg gas yield at 54.6% H₂+24.2% CO. The studied Fe₂O₃ oxygen carrier/rice straw is a feasible platform for syngas production from an agricultural waste.     

Characteristics of biomass gasification using chemical looping with iron ore as an oxygen carrier

Experiments regarding to biomass gasification using chemical looping (BGCL) were carried out in a fluidized bed reactor under argon atmosphere. Iron ore (natural hematite) was used as an oxygen carrier in the study. Similar to steam, a performance of oxygen carrier which provided oxygen source for biomass gasification by acting as a gasifying medium was found. An optimum Fe₂O₃/C molar ratio of 0.23 was determined with the aim of obtaining maximum gas yield of 1.06 Nm³/kg and gasification efficiency of 83.31%. The oxygen carrier was gradually deactivated with reduction time increasing, inhibiting the carbon and hydrogen in biomass from being converted into synthesis gas. The fraction of Fe²⁺ increased from 0 to 47.12% after reduction time of 45 min, which implied that active lattice oxygen of 49.75% was consumed. The oxygen carrier of fresh and reacted was analyzed by a series of characterization methods, such as X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDX).     

Syngas production by chemical looping gasification of rice husk using Fe-based oxygen carrier

The chemical looping gasification (CLG) of rice husk was conducted in a fixed bed reactor to analyze the effects of the ratio of oxygen carrier to rice husk (O/C), temperature, residence time and preparation methods of Fe-based oxygen carriers. The yield of gas, H₂/CO, lower heating value of syngas (LHV), conversion efficiency and performance parameters were analyzed to obtain CLG reaction characterization and optimal reaction conditions. Results showed that when O/C increased from 0.5 to 3.0, the gas production, H₂/CO, CO₂ yield and carbon conversion efficiency gradually increased, while the yield of H₂, CO and CH₄ and LHV gradually decreased. At the same time, a highest gasification efficiency was obtained when O/C was 1.5. As increasing temperature, the gas production, CO yield, carbon conversion efficiency and gasification efficiency gradually increased, while the yield of H₂, CH₄ and CO₂, H₂/CO and LHV gradually decreased. Sintering and agglomeration was obvious when the temperature was higher than 850 °C. When the reaction time increased from 10 min to 60 min, the gas production, CO yield, carbon conversion efficiency and gasification efficiency gradually increased, but the yield of H₂, H₂/CO and LHV decreased, among which 30 min was the best reaction residence time. In addition, coprecipitation was the best preparation method among several preparation methods of oxygen carrier. Finally, O/C of 1.5, 800 °C, 30 min and coprecipitation preparation method of oxygen carrier were the optimal parameters to obtain a gasification efficiency of 26.88%, H₂ content of 35.64%, syngas content of 56.40%, H₂/CO ratio of 1.72 and LHV of 12.25 MJ/Nm³.     

Reactivity investigation on biomass chemical looping conversion for syngas production

Chemical looping gasification (CLG) is regarded as an innovative and promising technology for producing syngas. In this work, CLG of straw was conducted in a fixed bed reactor with Fe₂O₃ as the oxygen carrier, whose results led to conclusions that Fe₂O₃, the oxygen carrier, proved advantageous to the secondary gasification reaction and the formation of CO and CO₂. It was also found that CO was further oxidized to CO₂ at high Fe₂O₃/C molar ratio, which resulted in a decreased gasification efficiency and low heat value of syngas. Therefore, a conclusion was drawn that the most optimized Fe₂O₃/C molar ratio was 0.2. In addition, the alkali metals in the biomass evaporated as chlorine salts into gas phase and retained as alkali metal oxide at high temperature, resulting in coking, slagging and heating surface corrosion. In the mean time, the oxygen carrier mainly converted to Fe and sintering phenomenon was serious at high temperature despite the fact that high temperature promoted gas yield, carbon conversion efficiency and gasification efficiency. Therefore, the most optimized temperature was set to 800 °C in order to maximize gas yield and gasification efficiency.     

The effect of oxygen carrier content and temperature on chemical looping gasification of microalgae for syngas production

The study of the effect of oxygen carrier content and temperature on chemical looping gasification (CLG) of Chlorella vulgaris was carried out in a fixed bed reactor. In order to obtain the characterization and optimal conditions of CLG for syngas production, this paper analyzed the product fractional yields, gaseous yields, conversion efficiency, SEM, XRD and composition analysis of oxygen carriers. The results indicated that CLG had a greater performance on gasification characteristics. When O/C increased from 0.5 to 3.0, gas yield, CO₂ yield and carbon conversion efficiency increased gradually, but LHV, H₂ and CH₄ yields decreased. Meanwhile, CO yield and gasification efficiency increased firstly and then decreased. Oxygen carrier Fe₂O₃ exhibited the characteristics of step-wise reduction (Fe₂O₃ → Fe₃O₄ → FeO) in CLG process. More FeO were generated at O/C of 0.5 and then caused serious sintering and agglomeration. High temperature was helpful to improve gas yield, carbon conversion efficiency and gasification efficiency. However, higher temperature would cause sintering and then weaken the activity of oxygen carrier. Moreover, under the experimental condition, O/C of 1.0 and 800 °C were the optimal parameters to obtain a high conversion efficiency of biomass, high products yield, good LHV and great reducibility of oxygen carrier.     

Advances in the application of active metal-based sorbents and oxygen carriers in chemical looping biomass steam gasification for H2 production

Active metal-based materials (AMMs) as CO₂ sorbents or oxygen carriers (OCs) have been investigated to enhance hydrogen production during various biomass-based chemical looping processes. CaO-based sorbents and Fe-based OCs are widely used in this field; therefore, these two types of materials will be the focus of this review. CaO-based sorbents can promote the water-gas shift reaction towards H₂ generation with in-situ CO₂ removal. OCs partly oxidise biomass, releasing CO – a reactant in the water-gas shift reaction. The use of Fe-based OCs boosts H₂ yield via iron-steam reactions. AMMs possess catalytic activity for tar cracking, generating more H₂. However, these AMMs suffer from sintering over cycles, which hinders their utilisation at industrial scales. The addition of support materials aims to overcome this issue. This review first assesses the impacts of CaO sorbents and OCs on H₂ production, and then examines the material behaviour, cyclic performance and applications in biomass-based chemical looping processes. The mechanism of support materials as a reactivity enhancer and sintering inhibitor is proposed in the review. The effects of operating conditions on H₂ yield are summarised and provided in the Supplementary materials.     

基于铁矿石载氧体的生物质化学链气化机理研究

在单批次进料小型流化床上,以稻壳为生物质燃料,研究了床料、气化温度、水蒸气体积分数以及载氧体载氧量与生物质含碳量的摩尔比(O/C)对生物质化学链气化反应特性的影响,并考察了铁矿石的长期交替氧化还原过程中的反应特性,分析了在小型流化床,水蒸气气氛气化条件下,铁矿石载氧体在反应过程中主要的反应以及反应后的铁矿石的床料变化。研究表明:在载氧体条件下,生物质的碳转化率显著增大,随着反应温度的升高,合成气中的H_2和CO的体积分数也相应升高。在温度不变情况下,随着水蒸气比例的升高,CO_2和H_2的体积分数显著上升。伴随着O/C摩尔比的升高,CO和H_2均显著下降。因此,在不同的反应条件下,铁矿石在生物质化学链气化过程中对反应速度、合成气比例等均有明显的作用,对研究生物质的综合利用具有一定的意义。     

Reactivity of Co-doped Ca2Fe2O5 brownmillerite oxides as oxygen carriers for microalgae chemical looping gasification

Chemical looping gasification (CLG) is a promising technology to covert solid fuel into synthesis gas efficiently, and oxygen carrier is crucial for CLG. In this work, Co-doped Ca₂Fe₂O₅ brownmillerite oxides were synthesized, and its reactivity as oxygen carriers for microalgae CLG was investigated. The results showed that the Cobalt substitution for Fe improved the activity of oxygen carriers, but excess Cobalt tended to complete oxidation. XPS analysis, thermogravimetric and fixed bed tests indicated that Cobalt doping enhanced the activity of Fe cations in brownmillerite structure, and Ca₂Fe_1.8Co_0.2O₅ was proved to be most suitable for microalgae CLG with the highest H₂ yield. In the initial 10 redox cycles, gasification performance with Ca₂Fe_1.8Co_0.2O₅ oxygen carrier almost kept stable, and the gasification efficiency and carbon conversion respectively dropped by 3.96% and 2.34%, although impurity phase of spinel oxide and agglomeration was detected. In summary, Ca₂Fe_1.8Co_0.2O₅ kept great activity and acceptable stability for synthesis gas production through microalgae CLG.     

Evaluation of redox activity of brownmillerite-structured Ca2Fe2O5 oxygen carrier for chemical looping applications

The brownmillerite-structured Ca₂Fe₂O₅ oxygen carrier has shown its great potential in chemical looping processes, due to it can be completed regeneration in a H₂O or CO₂ atmosphere without the air reactor. However, the low reaction reactivity of Ca₂Fe₂O₅ restricts its application. In this study, Ca₂Fe₂O₅ oxygen carrier was prepared by sol-gel method. The reduction and oxidation kinetics of Ca₂Fe₂O₅ were evaluated in H₂ and CO₂ atmospheres, respectively. The reduction of Ca₂Fe₂O₅ in H₂ atmosphere in good agreement with the random nucleation and growth model with E_a and A of 53.82 kJ/mol and 2.65 s⁻¹, respectively. The dimension of the model increases with conversion (A1.5 → A2 → A3 → A4). The oxidation of reduced Ca₂Fe₂O₅ in CO₂ atmosphere can be described by the zero-order contraction model with E_a and A of 11.66 kJ/mol and 0.05 s⁻¹, respectively. The kinetics analysis showed that both the reduction of H₂ and the oxidation of CO₂ are one-step reactions, as evidenced by the fact that only Fe⁰ and Fe³⁺ phases were detected in semi-in situ XRD analysis. It was inferred that the release and recovery of lattice oxygen is from inside to outside for Ca₂Fe₂O₅ oxygen carrier in the redox process. By reducing the migration energy barrier of lattice oxygen between bulk and surface would be an effective means to improve the reactivity of Ca₂Fe₂O₅ oxygen carriers.     

Methanol solution promoting cotton fiber chemical looping gasification for high H2/CO ratio syngas

Chemical looping gasification (CLG) is expected to act as an efficient novel technique realizing energy conversion, but solid fuel CLG suffers from inadequate fixed carbon conversion. Sufficient oxidant would be the grand cure for the torment that ever besets solid fuel CLG. We here reported a strategy to promote cotton fiber CLG to produce syngas with high H₂/CO ratio by introducing methanol solution for supplying adequate H₂O and CO. Experiments were performed under various oxygen excess number (Ω) at 850 °C. Ω around 0.3 favors the generation of syngas with high H₂/CO ratio and high carbon conversion (η). Comparatively experiments concerning effect of methanol solution on cotton fiber CLG verified its significant promotion on syngas generation. Methanol solution can even play a more significant role than water to increase the H₂/CO ratio and η from 5.64 to 71% to 6.82 and 87%, respectively, while H₂/CO ratio and η for the direct cotton fiber CLG without water and methanol solution is only 1.28 and 29%. Stoichiometry and thermodynamics analysis further verified the possibility of cotton fiber CLG using methanol solution, which shows a double advantage of waste solution treatment and energy conversion.     

Chemical looping gasification of cotton stalk with bimetallic Cu/Ni/olivine as oxygen carrier

Bimetallic Cu/Ni/olivine oxygen carriers (OCs) were prepared using olivine as support material for chemical looping gasification (CLG). The cyclic redox behaviors and oxygen carrying capacity (R_o) of OCs were evaluated by thermo-gravimetric analysis. The effect of Cu/Ni ratio, gasification temperature, steam to biomass ratio (S/B), oxygen carrier to biomass ratio (OC/B) on CLG of cotton stalk has been studied in a fixed bed. The OCs characterized using BET surface area, scanning electron microscopy (SEM), X-ray diffraction (XRD), temperature-programmed reduction (TPR) to investigate the physicochemical property of OCs during CLG. Result shows that the sintering problem of OC was progressively alleviated with the increasing Cu/Ni ratio. The olivine behaves as suitable OC support with oxygen carrying capacity of 1.07%. The redox reactivity of all of the OCs kept well during multiple redox cycles. The R_o of OCs progressively increased with the Cu/Ni ratio. By comparing the product gas concentration, carbon conversion, H₂ + CO yield and gas yield over the invested OCs, the Cu9/Ni6/O was found to demonstrate better comprehensive CLG performance due to the synergistic effect of Cu and Ni. The maximum gas yield, H₂ + CO yield and carbon conversion with Cu9/Ni6/O can be obtained at the S/B of 0.8 and OC/B of 2. Compared to theoretical value, 65% of lattice oxygen has been supplied by Cu9/Ni6/O during actual CLG process. The OC displayed better reactivity due to basic crystalline phase being preserved well during multiple CLG cycles.     

Chemical looping gasification for hydrogen production: A comparison of two unique processes simulated using ASPEN Plus

The research compares the simulations of two chemical looping gasification (CLG) types using the ASPEN Plus simulation software for the production of H₂. The simulated biomass type was poultry litter (PL). The first CLG type used in situ CO₂ capture utilizing a CaO sorbent, coupled with steam utilization for tar reforming, allowing for the production of a CO₂-rich stream for sequestration. Near-total sorbent recovery and recycle was achieved via the CO₂ desorption process. The second type utilized iron-based oxygen carriers in reduction–oxidation cycles to achieve 99.8% Fe₃O₄ carrier recovery and higher syngas yields. Temperature and pressure sensitivity analyses were conducted on the main reactors to determine optimal operating conditions. The optimal temperatures ranged from 500 to 1250 °C depending on the simulation and reactor type. Atmospheric pressure proved optimal in all cases except for the reducer and oxidizer in the iron-based CLG type, which operated at high pressure. This CLG simulation generated the most syngas in absolute terms (2.54 versus 0.79 kmol/kmol PL), while the CO₂ capture simulation generated much more H₂-rich syngas (92.45 mol-% compared to 62.94 mol-% H₂).     

Numerical and experimental investigation of hydrogen-rich syngas production via biomass gasification

In this work, the relation between hydrogen-rich syngas production and the gasification parameters such as equivalence ratio (ER), gasification temperature and biomass moisture content were studied. Stoichiometric equilibrium model that developed during this study was used to investigate the optimum hydrogen output generated from woody biomass in a fixed bed downdraft gasifier by considering the thermodynamic equilibrium limit. The mathematical model, based on thermodynamic equilibrium is necessary to understand complicated gasification process that will contribute to obtain maximum attainable hydrogen production. The effects of different oxidizing agents on the hydrogen concentration in the product gas as well as the effect of various air-biomass, oxygen-biomass and steam-biomass ratios were investigated. For validation, the results obtained from the mathematical model were compared with the experimental data obtained from the gasifier that uses air as gasification medium. The validated mathematical model was used to represent the gasifier that uses both oxygen and air-steam mixture as the gasification medium and the theoretical results were obtained for both cases. The theoretical results clearly show that the gasification process specially ones that use the air-steam mixture as the gasification medium can be used for hydrogen production.     

Activating Fe2O3 using K2CO3-containing ethanol solution for corn stalk chemical looping gasification to produce hydrogen

Alkaline organic liquid waste was introduced to activate Fe₂O₃ and provide sufficient steam to boost biomass chemical looping gasification (CLG) for H₂ production. Experiments under different excess oxygen ratios, temperatures, and alkali contents were performed to investigate the reaction characteristics of alkaline organic waste - biomass CLG. The highest H₂ yield of 1.71 L and carbon conversion rate of 83.8% were obtained at the excess oxygen ratio of 0.2, the alkali concentration of 6%, and the reaction temperature of 800 °C. Moreover, the kinetic and thermodynamic analysis under the optimized condition have cast light on the fundamental understanding of alkaline organic liquid waste - biomass CLG. Results demonstrate that this novel approach has the potential to enhance energy conversion.     

Bauxite waste with low Fe2O3 and high Na concentration as a promising oxygen carrier in chemical looping combustion

Development of a cost-effective oxygen carrier (OC) for chemical looping combustion (CLC) technology remains an important task to be accomplished. Bauxite waste red mud from the United States has shown promise as an OC, but bauxite waste from China has not been evaluated extensively although huge quantities of it exists. In comparison, the Chinese bauxite waste usually contains low Fe₂O₃ and high Na concentration. Hence, the purpose of this study was to evaluate a typical red mud (from Zibo, China) with low Fe₂O₃/Na mass ratio for its potential as a cost-effective OC during CLC processing. Parametric reactor testing was accomplished with a focus on OC reactivity during CLC, and evaluations were accomplished of morphologies, elemental concentrations, and mechanical strengths before and after reaction testing; special attention was paid to the stability of Na. These results showed that Zibo red mud (a) used as an OC during CLC had satisfactory reactivity particularly after pre-calcination at 1250°C, (b) had high contents of Na that were stable and uniformly distributed during reaction testing and formed NaAlSiO₄ during sample calcination and reaction testing, and (c) showed high mechanical strengths that were similar to those of other oxygen carriers. Considering that huge amounts of this inexpensive Zibo red mud are located within areas near aluminum processing plants, it may become a promising material as an OC for CLC processing.     

Interaction of coal ashes with potassium-decorated Fe2O3/Al2O3 oxygen carrier in coal-direct chemical looping hydrogen generation (CLHG)

Coal-direct CLHG is a novel hydrogen production technology with inherent CO₂ capture. Potassium-decorated Fe₂O₃/Al₂O₃ oxygen carrier (OC) has been proved to be a potential OC for the technology. However, the ash in the coal could influence the OC performance. In this work, the effect of ash addition on the reactivity, the morphology structure and phase composition of OC, and the potassium migration in the reduction stage were investigated. Furthermore, the effect of OC on the ash fusion temperature was discussed. Results indicated that the OC reactivity had no significant change when SM (Shenmu) ash addition was less than 1% in the reduction stage and decreased when the addition was more than 2%. In the steam oxidation stage, the H₂ yield varied between 5.80–5.57 mmol/g when the SM ash addition was less than 10% and decreased to 4.31 mmol/g when the addition was 40%. FeO could react with SiO₂ deriving from coal ash to form Fe₂SiO₄, which could cause the loss of Fe and the OC sintering; K₂CO₃ could react with silicon-aluminum minerals which could cause the potassium loss. The ash with high CaO content had a less negative effect on the OC reactivity. With the increase of SM ash addition, the potassium in OC decreased, the potassium in char increased and the volatile potassium decreased after the reduction stage. After the OC addition, the deformation temperature decreased from 1242 °C to 1114 °C in the weak reduction atmosphere while increased from 1162 °C to 1300 °C in the air atmosphere.     

Chemical looping reforming of ethanol-containing organic wastewater for high ratio H2/CO syngas with iron-based oxygen carrier

This work focused on chemical looping reforming (CLR) of ethanol-containing wastewater using iron-based oxygen carrier for high ratio H₂/CO syngas. Effects of various operating parameters on CLR experiments have been investigated. High temperature promotes the reactivity of oxygen carrier and release more lattice oxygen for CLR of ethanol-containing wastewater to realize maximum carbon conversion. 5% ethanol-containing wastewater, closed to the actual concentration of alcohol distillery wastewater, favors syngas yield. Ethanol-containing wastewater CLR processes could be divided into three stages, including the catalytic cracking, combination of catalytic cracking and reforming, and mainly catalytic reforming of ethanol, corresponding to three reduction periods Fe₂O₃ → Fe₃O₄, Fe₃O₄ → Fe₂O_2.45, and Fe₂O_2.45 → FeO, respectively. The whole process of ethanol-containing organic wastewater CLR is exothermic. Reaction heat released from the oxidation process of the reduced oxygen carrier can meet heat demand for CLR process. Ethanol-containing organic wastewater CLR opens up a new direction for hydrogen generation and waste treatment.